1. Field of the Invention
Not Applicable
2. Description of the Related Art
Thermoelectric generator devices can be used to create electrical energy based on temperature differentials. Many different thermoelectric materials and forms are known. It is often desirable to operate a thermoelectric generator over a large temperature gradient to increase higher thermal to electrical efficiency. For example, thermoelectric generators may be used in applications such as deep space missions, where other generators might have difficulties in operation.
No single thermoelectric material has been suitable for use over a very wide range of temperatures, e.g. such as between 300 and 1000 degrees Kelvin. Prior art techniques have used different thermoelectric materials and have been limited to relatively narrow temperature ranges. Each material is used in the range where it possesses the optimum performance.
Generators are known which include a multistage thermoelectric generator where each stage operates over a fixed temperature difference and is electronically insulated but thermally in contact with the other stages. An alternative approach uses segmented unicouples/generators, having p and n type materials, formed of different material segments but joined in series.
The present system describes a generator or unicouple formed of segmented thermoelectric parts. The unicouple may be formed of special thermoelectric materials including skutterudites, Zn4Sb3 materials and BiTe based materials. Specific materials may include Zn4Sb3 materials, CeFe4Sb12 based alloys, both of which are p type materials. N type materials may also be used including CoSb3 based alloys.